My mother and mother-in-law think I’m crazy to put my son to sleep on his back. They’re sure he’ll choke. Until recent “Back to Sleep” campaigns, conventional Western wisdom taught that babies should sleep on their stomach for fear of choking. I dutifully recorded it as my own advice to parents in my book Nighttime Parenting, published in 1985. But it turns out that not only is aspiration (inhaling of milk, food or spit-up into the lungs) or choking rare, but SIDS experts no longer even consider it a possible cause of SIDS. In fact, studies show that after a change from front to back sleeping, there was no increase in aspiration; in fact, the problem may have even decreased.
Another reason for the front-sleeping preference was the observation of mothers, confirmed by researchers, that many babies settled better, slept better, and cried less when placed to sleep on their tummies. It seems newborns settle better on their stomachs or sides because they feel more contained and are less vulnerable to startle. Because we are a culture whose parenting practices have traditionally fostered an uninterrupted night’s sleep, it seems odd to put our babies to sleep in a position that might encourage them to wake up more easily. Conventional parenting wisdom says, “Why change what works? Let sleeping babies lie.” In a 1992 survey of two thousand United States households, 74 percent of infants slept prone, 14 percent slept on their sides, and 12 percent on their backs. For a culture that treasures its sleep, this change will require some savvy public relations.
Some babies sleeping on their tummies also seemed to settle better and spit- up less after feeding. If an infant has gastroesophageal reflux, it is still recommended that he sleep tummy down, at least for two hours after a feeding.
Martha, my wife, believes there is another reason why babies are put to sleep on their tummies. If a mother is putting her baby to sleep, rather than parenting her to sleep, the front position works better. Many babies do not like being flat on their backs when they are tired, and most babies will resist by crying when they are plunked down this way awake. When put tummy-down, a baby is more able to comfort herself off to sleep by assuming the fetal position and sucking on her fingers. A front position would also encourage a baby who does awaken to return to sleep on her own.
A final reason for the traditional front-sleeping position is that new mothers see nurses put babies down this way in the hospital, and mothers often do what they see nurses do. (Also, young doctors in training see nurses place newborns to sleep on their stomachs, so they pass on this habit to the mothers in their practice, and the cycle continues.) Nurses are accustomed to putting babies to sleep on their tummies because that’s what they have learned is best for premature babies or babies with breathing difficulties; the still partially collapsed lungs of some prematures tend to expand better when front-sleeping. Yet this benefit is only for preterm babies and babies with breathing difficulties. Once babies are well and at home, the front-sleeping position is unlikely to benefit their breathing.